1. Field of the Invention
The present invention relates to an improved process or method for applying a coated or uncoated film onto at least one main surface of a lens substrate which can be implemented in a short period of time without any risk of deformation of the lens substrate which avoids the use of a light or thermal curing adhesive during the application of the film onto the main surface of the lens substrate.
2. Description of Related Art
It is a common practice in the art to coat at least one main surface of a lens substrate, such as an ophthalmic lens or lens blank, with several coatings for imparting to the finished lens additional or improved optical or mechanical properties.
Thus, it is usual practice to coat at least one main surface of a lens substrate, typically made of an organic glass material, with successively, starting from the surface of the lens substrate, an impact-resistant coating (impact resistant primer), an abrasion and/or scratch-resistant coating (hard coat), an anti-reflecting coating and, optionally, a hydrophobic top coat. Other coatings such as a polarized coating, a photochromic or a dying coating may also be applied onto one or both surfaces of the lens substrate.
Numerous processes and methods have been proposed for coating a surface of an ophthalmic lens and are disclosed.
U.S. Pat. No. 6,562,466 describes one process or method for transferring a coating from at least one mold part onto at least a geometrically defined surface of a lens blank comprising:                providing a lens blank having at least one geometrically defined surface;        providing a support or mold part having an internal surface bearing a coating and an external surface;        depositing on said geometrically defined surface of said lens blank or on said coating a pre-measured amount of a curable adhesive composition;        moving relatively to each other the lens blank and the support to either bring the coating into contact with curable adhesive composition or bring the curable adhesive composition into contact with the geometrically defined surface of the lens blank;        applying a sufficient pressure onto the external surface of the support so that the thickness of a final adhesive layer once the curable composition cured is less than 100 micrometers;        curing the layer of adhesive composition; and        withdrawing the support or mold part to recover the lens blank with the coating adhered onto the geometrically defined surface of said lens blank.        
In the process of U.S. Pat. No. 6,562,466, a light or thermal curing adhesive is used to transfer the coating layers from the support to the surface of the lens substrate. The adhesive is required to stick both to the exposed film on the support and the surface of the lens substrate.
Using a chemical adhesive has several drawbacks regarding toxicity, handling, environment and cost.